Inhibition Effects of Nitrones on the Corrosion of Mild Steel in Organic Acid Media

Abstract

Aromatic nitrones have been synthesized and investigated for their function as inhibitor for the corrosion of mild steel in the organic acid media-20% formic acid and 20% acetic acid at various inhibitor concentrations in the range of 50-150 ppm. Weight loss measurements and potentio-dynamic polarization studies reveal that the nitrones behave as mixed type inhibitors. Among the nitrones tested, para-methyl substituted derivatives perform better as inhibitors than the un-substituted nitrones.

Evaluation of the corrosion inhibiting efficacy of a newly synthesized nitrone against St37 steel corrosion in acidic medium: Experimental and theoretical approaches

“…The electron-donor N-oxide oxygen atom of a nitrone makes it suitable for complexation and protonation. The nitrone molecules tend to be adsorbed on to the mild steel substrate as a negatively charged species which can form a complex with the positive metal cation Fe 2+ [33]. The corrosion inhibition of the synthesized amphiphilic nitrone in 1.0 M HCl may be due to the adsorption of this compound on the metal surface by the following interactions [64].…”

“…Depending on the length of the hydrocarbon chain non-polar van der Waals interactions provide better barrier against aggressive environments. Although many organic corrosion inhibitors are known in the literature, study on the corrosion inhibition properties of nitrones is far less [33][34][35]. In addition, no study has been undertaken on the corrosion inhibition by amphiphilic nitrones to the best of our knowledge.…”

Synthesis and Application of Phenyl Nitrone Derivatives as Acidic and Microbial Corrosion Inhibitors

“…It has been reported that some nitrone compounds can form stable complexes with Cu(II), Ni(II), Co(II), and Cr(III) ions [10], which is useful during the acidic corrosion inhibition for the inhibitors interacting with the metal, so they may be potential corrosion inhibitors. Some N-diphenyl nitrones have been used as corrosion inhibitors for mild steel in organic acid media, and they were found to be with moderate to high inhibition in 20% formic acid/acetic acid under the concentration of 50 to 150 ppm [11]. It should be noticed that, for most corrosion, the microbiologically influenced corrosion (MIC) cannot be avoided especially in oilfield, so it will be an interesting work to develop inhibitors against acidic corrosion and MIC.…”